What is the baseline in typography?

The baseline in typography refers to the invisible line upon which most letters rest. It serves as the foundational reference point in text layout, ensuring that letters align consistently across a line of type. This concept is essential for maintaining visual coherence in typography, as it allows for proper spacing and alignment of characters in different typefaces.

While discussing the options, it's crucial to note that the top line of text represents a different aspect of typography—the cap height or ascender line where uppercase letters reach. The middle line of text is not a standard term in typography and does not refer specifically to any universally recognized element. Similarly, the height of uppercase letters pertains to the specific dimension of capital letters in a typeface rather than the baseline itself. By understanding that the baseline is where the majority of text aligns at the bottom, one can appreciate its role in creating organized and legible text blocks.